The network ACROPOL was originally developed by the company Airbus Defence and Space, part of the group Airbus and installed in all departments since 1994.
It is part of theINPT (National shareable transmission infrastructure) which is the national digital radiocommunication network. It is intended to ensure interoperability of emergency services, that is to say exchanges between police, gendarmerie, firefighters, SAMU, Civil Security. This radio network operates in the 380-410 MHz band on a technology TETRAPOL.
TETRAPOL is a digital radiocommunication standard, mainly implemented in equipment used by security forces.
The INPT is used by ACROPOL (police), ANTHARES (firefighters) and RUBY (Gendarmerie) for civil security operations.
What is ACROPOL?
ACROPOL is a network unique and national radio, allowing a user, from all over the country, to access all the services, whether through a landline or on board a vehicle. Conversely, each official can be reached anywhere by simply dialing his extension number.
The advantages of ACROPOL are based on:
- the phonic clarity of the message (cannot be intercepted by third parties outside the ACROPOL network)
- a great confidentiality due to encryption
- the possibility of triggering a emergency call in case of distress at the touch of a button.
When establishing a call, the Information and Command Center (CIC) decides to activate a called radio channel conference. Each open conference is assigned a ID number. Field agents’ radios are recognized through continuous communication.
Each conference operates in mode trunking (Secure calls limiting the risk of outage): during transmission, it can be shared over time on the same channel TRX (transmitter allowing muti-communication), on the other hand the frequency does not change periodically like the frequency hops of certain public GSM networks. If the policeman changes geographical sector and passes under the antennas of a new relay, there is no handover, but a search is carried out on the beacon lane. Only tactical voice communications between portable telephones do not use the relay trunking process since the communication is interpersonal.
Each official can, via an on-board terminal (TESA) connected to the network, on the site of a public road event, record and transmit all the elements for the action as for the archiving, establishing the sort of “computerized handrail” without having to repeat this gesture of return to his service.
Réseau Radio Futur, the new mobile radio?
Acropol is part of theINPT with RUBY and ANTARES.
Following the cut-offs of emergency calls, the INPT has to evolve, because it is considered disappointing and unreliable by users. The project RRF (Réseau Radio du Futur) aims to build a national high-speed priority mobile communication system.
This communication service must be operational no later than 2023. Indeed, it is supposed to be in service during the course of the 2023 summer rugby world cup then Paris Olympic and Paralympic Games in 2024.